Process of and apparatus for making a shingle, and shingle made thereby

ABSTRACT

A process and apparatus for making a shingle, together with the shingle made thereby, is provided, in which one or more thermoplastic materials are extruded or co-extruded to form an extrudate, with the extrudate being cut into a preliminary shingle shape, which is allowed to dissipate heat, and then is delivered to a compression mold, wherein the preliminary shingle shape is compression molded to substantially its final dimensions and is then discharged from the mold and allowed to cool.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 10/452,059, filed Jun. 2, 2003, the complete disclosure ofwhich is herein incorporated by reference.

BACKGROUND OF THE INVENTION

In the art of making roofing shingles and tiles for exterior applicationin the building industry, various approaches have been made towardmaking shingles and tiles that are manufactured, but give the appearanceof being made of traditional natural materials, such as wood cedarshakes, tiles, slate, etc.

In many instances, such shingles and tiles are made of bitumen coatedmat having granules on the exterior surface, with the granules beingprovided in various designs, shades, color configurations, etc., toyield various aesthetic effects.

It is also known, in making roofing shingles and tiles, to mold them tothe desired shape by various molding techniques. The materials that areused in such molding techniques usually include inexpensive fillermaterial, in order to achieve low production costs.

Some such filler materials can be various waste products, such as carbonblack, recycled rubber and tire crumb, coal fines, pulp and paper wasteand other inexpensive materials.

Such products are often made by molding multi-component formulations,which comprise blends of virgin and recycled polymers and variouslow-cost fillers.

The use of large quantities of such fillers reduces the mechanicalproperties of the ultimate product, however. Additionally, the use oflarge quantities of fillers limits the color variations that arepossible in the products and makes the processing of the formulationsinto shingles and tiles very difficult.

Typically, roofing shingles and tiles made of such material having wastefor filler do not provide good weather resistance for the products.Additionally, the warranty periods that can reasonably be provided forsuch products tend to be short in duration.

Furthermore, such building industry roofing products have relatively lowimpact strength, especially at low temperatures. Insofar as theiravailable colors are concerned, such tend to be limited to the colorsgray and black.

Additionally, molding operations tend to be capital intensive, withrelatively high manufacturing costs, although molding techniques doprovide a high level of definition or dimension control. Also, there isa disadvantage to molding techniques, in general, in that the length ofthe cycle for injecting material into the mold, molding to the desiredshape, and ejecting the shape from the mold is largely a function of thetime required to cool the molten thermoplastic material before it can beremoved from the mold. However, the temperature of the thermoplasticmaterial must be sufficiently high that it can flow and fill the cavitywithin the constraints of the material and equipment (i.e. materialcharacteristics, melt pressures, mold clamping pressures, etc.). Whilemodifications can be made to the materials to help the flowcharacteristics and thereby lower the required melt temperature, andwhile improvements can be made to the mold to increase heat transfer andremoval, cooling remains the longest part of the cycle for theseprocesses. In order to achieve the necessary cooling, the time requiredcauses a lengthening of the manufacturing cycle, which increases thecapital costs of investment in molds and machinery for a requiredoutput, thereby substantially increasing manufacturing costs.

SUMMARY OF THE INVENTION

The present invention is directed to a process of making a shinglehaving a desired configuration, by a combination of extruding andmolding, in order to reduce the time required for the molding operation.As used throughout the application, “shingle” should be considered toembrace “tile” also.

It is a further object of this invention to accomplish the above objectby co-extruding the shingle to include a core material with a shinglecapstock material on a major surface.

It is a further object of this invention to accomplish the aboveobjects, in which the extruding step is a continuous process, and inwhich the extrudate is serially cut into discrete preliminary shingleshapes, prior to molding those shapes into the final shingle shape.

Additional objects of this invention include producing shingles by theprocesses described above.

Further objects of this invention include providing apparatus foraccomplishing the processes for producing shingles as described above.

Other objects and advantages of the present invention will be readilyapparent upon a reading of the following brief descriptions of thedrawing figures, detailed descriptions of the preferred embodiments, andthe appended claims.

BRIEF DESCRIPTIONS OF THE DRAWING FIGURES

FIG. 1 is a vertical, sectional view of a process and apparatus forextruding a preliminary shingle shape and serially severing theextrudate into a plurality of preliminary shingle shapes, for deliveryto a molding station, with the delivery means being fragmentallyillustrated at the right end thereof.

FIG. 2 is a top plan view of that which is illustrated in FIG. 1.

FIG. 3 is an illustration similar to that of FIG. 1, but wherein theextruding operation includes both core material and skin or capstockmaterial, being co-extruded prior to the serial severing step, with thedelivery means also being fragmentally illustrated at the right endthereof.

FIG. 4 is a top plan view of one embodiment which is illustrated in FIG.3, wherein the skin or capstock material covers a portion of the topsurface of the extrudate.

FIG. 5 is a schematic vertical elevational view of a compression moldingstation adapted to receive preliminary shingle shapes delivered from theright-most end of the illustrations either of FIGS. 1 and 3, forcompression molding the shapes into their final configuration.

FIG. 6 is a top view of the compression molding station of FIG. 5, takengenerally along the line VI-VI of FIG. 5, and with an indexable moldhandling table illustrated at the right end thereof, with a robot androbot arm being schematically illustrated for removal of shingles frommolds carried by the indexable table.

FIG. 7 is a schematic elevational view of upper and lower moldcomponents shown in the open position, at one of the stations on theindexable table, with the indexable table fragmentally illustrated, andwith a robot arm for lifting the finished shingle from the mold.

FIG. 8 is an enlarged generally plan view of an upper mold component,taken generally along the line of VIII-VIII of FIG. 5.

FIG. 9 is an enlarged generally plan view of a lower mold component,taken generally along the line of IX-IX of FIG. 5.

FIG. 10 is an enlarged vertical sectional view, taken through the upperand lower mold components, generally along the line X-X of FIGS. 8 and9.

FIG. 11 is a top perspective view of a finished shingle made inaccordance with this invention.

FIG. 12 is a vertical sectional view, taken through a shingle made inaccordance with this invention, generally along the line XII-XII of FIG.11, wherein the shingle is comprised of two single layers of material,one being a core layer and the other being a partial capstock or skinlayer.

FIG. 12 a is an illustration like that of FIG. 12, but wherein theshingle is comprised of three layers of material.

DETAILED DESCRIPTIONS OF THE PREFERRED EMBODIMENTS

Referring now to the drawings in detail, it will be seen that, inaccordance with this invention, the shingle or tile will first bepre-shaped by extruding a cross-section that will be generally similarto the finished cross-section of the shingle or tile, with thepre-shaped or preliminary shingle shape then being allowed to coolsomewhat prior to placement of it in the mold. By first getting thepreliminary shingle shape to conform closely to the final shingle shapebefore placing it in the mold, long flow distances and hence highermaterial temperatures are avoided. The material in the mold is thencompression molded to achieve its final dimensions. Because significantamounts of heat are removed prior to placement of the preliminaryshingle shape into the mold, very short cooling cycles are achieved.

In another embodiment, the amount of cooling is minimized prior toplacement in the mold. In this way, significant amounts of heat do notneed to be provided, thus the shortened cooling cycle is obtainable.Also, higher molecular weight polymeric materials with higherviscosities and better polymer performance properties, which would notnormally be useful in a molding operation such as injection molding, canbe used, because the shape of the precursor is close to that of themolded piece and the amount of material flow necessary to produce thedesired finished shingle shape is minimal.

Referring now to FIG. 1, it will be seen that an extruder is generallydesignated by the numeral 20 for receiving generally thermoplasticpellets 21 into an inlet hopper 22 thereof, and with an auger 23 beingrotatably driven, to urge the pellets through the extruder 20 in thedownward direction of the arrow 24, through the extruder, to bedischarged at discharge end 25. It is desirable to dry the pellets priorto adding them to the extruder in some instances, depending on thecomposition of the pellets. Such drying may include exposing the pelletsto a drying cycle of up to 4 hours, at an elevated temperature, such as,for example, 180° F. Suitable means, such as electric coils 26 areprovided for heating the thermoplastic material 21 in the extruder, sothat the same can be extruded into a desired shape as may be determinedby the outlet mouth 25 of the extruder 20. The extrudate 27 is thenmoved horizontally in the direction of the arrow 28, beneath atransverse cutting mechanism 30 in the form of a guillotine, which ismovable upwardly and downwardly in the direction of the double-headedarrow 31, with the blade 32 of the guillotine, operating against ananvil 29, to sever the extrudate 27 into a plurality of preliminaryshingle shapes 33. The shapes 33 then pass onto an upper run 34 of acontinuously moving conveyor belt 35 driven between idler end roller 36and motor-driven end roller 37, with the upper run 34 of the belt 35being supported by suitable idler rollers 38, as the preliminary shingleshapes 33 are delivered rightward, in the direction of the arrow 40illustrated in FIG. 1. In lieu of a guillotine 30, any other type ofcutting mechanism, such as for example only, a blade or other cuttermovable transversely across the belt 34, or the die lip at the dischargeend 25 of the extruder, in a direction perpendicular to the arrow 40 canbe used to separate the extrudate into a plurality of shapes 33. Thebelt which supports the shapes can be a vented belt made of a suitablematerial, such as, for example, a silicone coated belt, or a metal meshbelt, or the like, in order to control bubbling or outgassing of gassesfrom the extrudate, if desired.

It will be seen that in the embodiment of FIGS. 1 and 2, the preliminaryshingle shapes 33 are extruded into a single layer of material from theshingle extruder 20.

With reference now to FIGS. 3 and 4, it will be seen that the extrudate45 is cut into a plurality of multiple layer preliminary shingle shapes46, in that the process as shown in FIGS. 3 and 4 is a co-extrusionprocess, whereby a capstock or skin material 47 may be extruded throughextruder 48, while a core material 50 is extruded through anotherextruder 51, each with their own thermoplastic heating systems 52, 53,such that the discharge mouth 54 of the co-extruder 55 produces multiplelayer preliminary shingle shapes 46, as shown.

The other details of the apparatus as shown in FIGS. 3 and 4, includingthe guillotine, anvil, conveyor belt, rollers, etc. are all otherwisesimilar to the comparable items described above with respect to FIGS. 1and 2.

The conveyor will preferably have a take-off speed that is matched tothe extrusion speed, such that after extrusion of a given length, thecutting is effected by the guillotine or the like, and the speed of theconveyor can be controlled. Alternatively, two conveyors may be disposedserially, with the speed of the upper run of the first conveyor beingaccelerated to deliver the shapes to the second conveyor after cutting,with the speed of the first conveyor then being re-set to match theextrusion speed of extrudate leaving the extruder, with the secondconveyor being controlled for delivery of the shapes to the mold.Alternatively, rather than having the delivery being automatic, the samecould be done manually, if desired.

Thus, with reference to FIGS. 3 and 4, the multiple layer preliminaryshingle shapes 46 are delivered generally rightward, in the direction ofthe arrow 56.

It will be noted that the preliminary shingle shapes 46 that areco-extruded as shown in FIGS. 3 and 4 are illustrated as comprisingpreliminary shingle shapes comprising a core material 57 that issubstantially the full length of the shapes as shown in FIG. 4, with acapstock material 58 on an upper surface thereof, that is slightly morethan half the dimension of the full length of the shingle shapes 46shown, terminating at 60 as shown. Alternatively, capstock material 58could cover a lesser or greater portion of the upper surface, or eventhe entire upper surface of the shingle shape.

Referring now to FIG. 5, it will be seen that the shapes 46 or 33, asmay be desired, are delivered via the conveyor belt, in the direction ofthe arrow 61, to be placed between mold components in a press, to becompression molded as will be described hereafter. In lieu of a conveyorbelt, a moveable tray, a carrier, a platform or other means of supportedtransport could be used.

It will be noted that the extrusion and co-extrusion processes describedabove are continuous processes, and that the severing of the extrudateof whichever form by the guillotine is a serial, or substantiallycontinuous process, and that the delivering of the preliminary shingleshapes from the extruder or co-extruder along the conveyor belt allowsfor the dissipation of heat resulting from the extrusion process, fromthe preliminary shingle shapes, in that, by allowing the shapes tosubstantially cool prior to placing them in the mold, rather thanrequiring the cooling to take place completely in the mold itself,reduces the required time for residence of the shapes in the mold duringthe compression process, as will be described hereinafter.

It will also be noted that maintaining the temperature above a meltingtemperature so that a quick flow of the melt can occur in the mold isdesired in some embodiments. This maintaining of temperature above acrystallization or solidification temperature can minimize thedevelopment of internal stresses within the preliminary shingle shapesthat could be caused by deformation of polymers that have begun to enterthe solid state.

As the preliminary shingle shapes approach the right-most end of theconveyor belt as shown in FIG. 5, some suitable mechanism, such as thepusher rod 62, shaft-mounted at 63 and suitably motor-driven by motor64, and operating in a back-and-forth motion as shown by thedouble-headed arrow 65, pushes shapes 46 (or 33) rightward, in thedirection of the arrow 66, along table 67, to the position shown,between upper and lower mold components 68, 70, respectively.

The mold generally designated 71 in FIG. 5 and comprised of upper andlower mold components 68, 70, respectively, is movable into and out ofits position as shown at the center of the ram mechanism 72, in thedirection of the double-headed arrow 73, from an indexable table 74 thatwill be described hereinafter. The ram mechanism 72 operates like apress, wherein a ram 75 is pneumatically, hydraulically or electricallydriven, generally by means of a piston or the like within the upper endof the ram mechanism, for driving an electromagnet 76 carried at thelower end of the ram 75, for lifting the upper mold component 68upwardly as shown.

The closing of the mold can be done, at a force of, for example, 40tons, in order to cause a material flow out on the edges of the shinglebeing molded, for 3-4 seconds, with the entire molding process as shownin FIG. 5 taking approximately one minute, after which the cooling ofthe molded material can take place, followed by removal of the moldedmaterial (shingle) from the mold, for subsequent or simultaneoustrimming of the flashing therefrom. More preferably, a shorter moldingcycle of 45 seconds can also be used.

The two mold components 68 and 70, when moved from the closed positionon table 74 shown at the right end of FIG. 5, to the open position shownat the center of the ram mechanism 72 of FIG. 5, separate such that theupper component 68 is movable upwardly and downwardly along guide rods77, as the electromagnet 76 lifts a preferably ferromagnetic cap 78carried by the upper mold component 68, such that, in the open positionshown for the mold 71 in FIG. 5, a transfer mechanism 62 may move apreliminary shingle shape 46 (or 33) along the table 67 in the directionof the arrow 66, to a position between the open mold components 68, 70as shown.

The ram mechanism 72, itself, is comprised of a base member 80 and acompression member 81, and the member 81 carries the ram 75. Thecompression member 81 also moves vertically upwardly and downwardly, viaits own set of guide rods 82, in the direction of the double-headedarrow 83, and is suitably driven for such vertical movement by anyappropriate means, such as hydraulically, pneumatically, electrically(not shown).

With reference now to FIGS. 6 and 7, it will be seen that the mold 71may be moved to and from the ram mechanism 72, in the direction of thedouble-headed arrow 73, by any appropriate means, such as by means of ahydraulic or pneumatic push/pull cylinder 89, driving a rod 84, that inturn has an electromagnetic push/pull plate 85, for engaging theferromagnetic cap 78 of the upper mold component 68, as shown in FIGS. 5and 7.

The indexable table 74 is rotatably driven by any suitable means (notshown), to move mold assemblies 71 into position for delivering them toand from the ram station 72 as discussed above. In this regard, theindexable table 74 may be moved in the direction of the arrows 86.

If desired, in order to facilitate cooling, cooling coils may beembedded in, or otherwise carried by the table 74, such coils beingshown in phantom in FIG. 7, at 87, fed by a suitable source 88 ofcoolant, via coolant line 90, as shown. The coolant can be water,ethylene glycol, or any other useful coolant as may be desired.

Similarly, coolant coils are shown in phantom at 91 in FIG. 7 for thelower mold component 70 and may be provided with coolant from a suitablesource 92, if desired. Also, optionally, the upper mold component 68 maybe provided with internal coolant coils 93, shown in phantom in FIG. 7,likewise supplied by coolant from a suitable source 94.

Upon the shapes 33 or 46 entering the mold, they may have a surfacetemperature of 300° F.-320° F., with the temperature being hotter in thecenter of the core material. Upon leaving the mold, the surfacetemperature of the shapes will normally be in the range of 80° F.-85° F.

Within the mold, it is preferable to heat the top mold component 68(which will preferably engage the capstock material) to a slightlygreater temperature than that of the bottom component 70, in order tocontrol internal stress development. For example, the top component 68may be heated to 120° F., for example, with the bottom component beingheated to 70-80° F. The subsequent cooling for the top plate 68 could bea natural cooling by simply allowing heat to dissipate, and the bottomplate can be cooled, for example, by well water, at about 67° F.Alternatively, well water or other coolant could be circulated, firstthrough the bottom component 70 and then to the top component 68,however, in some instances it can be preferable to cool both components68 and 70 to the same temperature. It will also be understood thatvarious other cooling techniques can be employed to regulate temperatureat various locations in the mold, depending upon the thickness of theshingle being molded, in various locations of the shingle being molded,as may be desired.

At one of the stations shown for the indexable table 74, a liftingmechanism 95 may be provided, for opening the molds 71, one at a time. Atypical such lifting mechanism may include a hydraulic or pneumaticcylinder 96, provided with fluid via fluid lines 97, 98, for driving apiston 100 therein, which carries a drive shaft 101 that, in turn,carries an electromagnet 102 for engaging the cap 78 of the upper moldcomponent 68, as the drive shaft 101 is moved upwardly or downwardly asshown by the double-headed arrow 103.

The closing of the components 68 and 70 relative to each other couldalternatively be done under a force of 30 tons, rather the 40 tonsmentioned above, in order to obtain a consistent closing and flow ofmaterial. Alternatively, the closing could begin at a high speed, andthen gradually slow down, in order get an even flow at an edge of theshape that is being formed into a shingle.

When the mold 71 is in the open position shown in FIG. 7, and as isshown in greater detail in FIG. 10, a plurality of spring pins 105,mounted in lower mold component 70, in generally cylindrical cavities106 thereof, are pushed upwardly by means of compressed springs 107,such that the upper ends of the spring pins engage the compressionmolded shingle and pushed the same out of the lower mold cavity 108.

Similarly, spring pins 104 engage “flashing”, or other material that hasbeen cut away from the periphery of the formed shingle, for pushing thesame out of the trench 110 that surrounds the cavity 108 in the lowermold component 70.

As shown in FIGS. 9 and 10, the lower mold 70, has, at the periphery ofits cavity 108, an upstanding cutting blade 109 separating the moldcavity 108 from the peripheral trench 110, for cutting the preliminaryshingle shapes placed therein to the precisely desired dimensions of thefinal shingle, during the compression molding process. That is,generally, the preliminary shingle shapes may be slightly larger in sizethan the final shingle shape, to enable the cutting edge 109 to achievethe final desired dimensions for the shingle. The cutting of flashingfrom the shingle should be done quickly, and it is preferably done inthe mold. The flashing can be recycled back for re-use, most preferablyfor use as part of subsequent core material. While the trimming of theflashing can be done in the mold, it could, alternatively, be done as asecondary trimming and finishing operation which, in some cases may bemore cost effective than trimming in the mold.

Both the upper and lower mold cavities 111 and 108 are preferablyprovided with protrusions 112, 113, respectively, which protrusions willform reduced-thickness nailing or fastening areas in the compressionmolded shingle, as will be described hereinafter.

With the fully formed shingle as shown in FIG. 7 having been liftedupwardly out of a lower mold component 70 by means of the spring pins, acomputer control robot mechanism 119 or the like may control a roboticarm 114, having shingle-engaging fingers 115, 116, adapted to engageupper and lower surfaces of the compression molded shingle 117, and movethe same horizontally out from between upper and lower mold components68, 70, to another location for storage or delivery to another station,as may be desired.

Thereafter, the indexable table 74 may be moved, for delivery of a nextadjacent mold to the station for engagement by the lift mechanism 95,with the table 74, generally being rotatable on a floor 118, as allowedby a number of table-carrying wheels 120.

Referring now to FIGS. 8 and 9, specifically, it will be seen that theupper mold component 68 (FIG. 8) has a generally rectangular shapedupper mold cavity 111 that is essentially the shape of a natural slateshingle having a headlap portion 125 and a butt or tab portion 126. Itwill be noted that in the headlap portion there are a plurality ofprotrusions 112 that define reduced thickness areas in the compressionmolded shingle 117, to serve as nailing or fastening areas, to make iteasier for nails or other fasteners to penetrate the shingle 117 when itis nailed to a roof.

There are also a plurality of mold recesses or protrusions 127 as may bedesired, to build into the shingle 117 the appearance of a naturalslate, tile or the like. It will be understood that the number and styleof the recesses/protrusions 127 will be varied to yield anatural-appearing shingle having the desired aesthetics.

In the tab or butt portion of the shingle 126, there is a graduallysloped reduced-thickness portion 128 that appears in FIG. 8 to beU-shaped, and which defines the periphery thereof. This slopedreduced-thickness portion 128, as shown in FIGS. 8 and 10 will serve tocause the capstock layer of the preliminary shingle shape being engaged,to flow peripherally outwardly around the edges of the core layer ofmaterial, such that, in the finished shingle, the exposed edges will becovered by capstock material, as well as the exposed surface, such thatthe edges of the core layer of shingle are weather-protected.

With reference to FIG. 9, it will be seen that the lower mold component70 is provided with a lower mold cavity 108, also having protrusions 113therein, for effecting a reduced-thickness nailing or fastening area forapplying a shingle to the roof, in the final shingle 117. It will beunderstood that, alternatively, the mold cavity 111 could be the lowermold cavity and that the mold cavity 108 could be the upper mold cavity,if desired.

The spring pins 104, 105, and the trough 110 and mold depression 108,respectively, as described previously, are also shown in FIG. 9.

It will thus be seen that the two mold components 68 and 70 are thusadapted to compression mold a shingle such as that which is shown by wayof example only, in FIG. 11.

The shingle of FIG. 11 thus has a headlap portion 131 and a butt or tabportion 132, with relief or other aesthetically pleasing areas 133, asshown, and with the butt or tab portion 132 having a capstock or skin134 thereon, in the lower half of the shingle, terminating in uppercapstock edge 135, such that, when shingles 130 are installed on a roof,a next-overlying tab or butt portion of a shingle will cover the upperend, or headlap portion 131 of the shingle 130. Alternatively, thecapstock or skin 134 could cover a greater portion or even the entiretop surface 137 of the shingle 130 (not shown). For example, the edge ofthe capstock coverage could optionally extend to be coincident with theupper edge 139 of the shingle 130.

It will also be noted that there are nailing or other fastenerreduced-thickness portions 136, in the shingle of FIG. 11, and that theU-shaped periphery along the right and left sides and lower edge of theshingle 130 slope downwardly from the top surface 137 to the lowersurface 138, as shown at 140.

With reference now to FIG. 12, it will be seen that the slope of theedges 140 is at an angle “a”, as shown in FIG. 12, which angle “a” willpreferably be on the order of about 45 degrees (135 degrees betweensurfaces 137 and 140), and that such slope may be other than a straightline, such as having some aesthetic irregularity built into the shingle130, as shown at the left end of FIG. 12.

It will thus be seen that the skin or capstock material 134 cansubstantially encapsulate the tab or butt portion of the shingle ofFIGS. 11 and 12, that is to be the exposed portion of the shingle 130when the shingle is installed on a roof, leaving the core material 141to comprise a majority of the volume of the shingle 130.

In another embodiment, the skin or capstock material can substantiallyencapsulate the entire top surface of the shingle 130, the core materialcomprising a majority of the volume of the shingle 130. In thisembodiment portions of an underlying shingle between a pair of adjacentshingles in an overlying course are protected with the more durable skinor capstock material.

It will be understood that the core is preferably constructed of aninexpensive material, and that the capstock is preferably constructed ofa material, such as but not limited to, a polymer having a high weatherresistance and the ability to be colored in various colors, as well asdesirable ultraviolet characteristics. In this case where a capstockalso covers the upper portion or headlap area of the top surface of theshingle 130, the capstock on the upper portion may be of the same ordifferent color or appearance as that covering the lower portion 134.

It will also be understood that the shingle 130 may be constructed invarious other configurations, to have edges that are segmented,scalloped or the like, or as may be desired. The relief areas 133 maycomprise lines, grooves, or seemingly random relief, as may be desired,all to give the appearance of natural material such as slate, tile,cedar shake or the like. It will also be apparent that the shingles ortiles 130 may be constructed of various sizes as may be desired.

With reference to FIG. 12 a, it will be seen that a shingle 150 isprovided, also having a core material 151 and a capstock material 152,like that of the shingle 130 of FIG. 12, but wherein a third layer 153of another material is provided, that essentially sandwiches the corematerial 151 between the capstock material 152 and the third layer 153of material, in the tab or butt portion 154 of the shingle. The shingleof FIG. 12 a can be constructed as described in the processes above,especially with respect to the processes described in FIGS. 3 and 4,wherein there is a co-extrusion; however, the co-extrustion in the caseof the embodiment of FIG. 12 a would be in the form of three materiallayers rather than two layers, with the bottom layer 153 being comprisedeither of the same material as that of the capstock layer 152, or of adifferent, third layer.

The core material will generally be of greater thickness than the skinmaterial and will preferably be comprised of a highly filled polymer.The skin material will preferably be comprised of a polymer having highweather resistance and the ability to be colored in various colors asmay be demanded by building designers.

The relative thickness of the capstock material to that of the corematerial can be about 10%, although, if additional capstock thickness isdesired, one can increase this relative thickness up to about 20%. Theminimum thickness of the capstock material should be on the order ofabout 4 mils, and the range for the same could be from about 4 mils upto about 10 mils. In some instances, a 5% ratio of capstock material tothe total thickness of the shingle can suffice, such that the capstockmaterial would comprise 5% of the total thickness, with the corematerial comprising 95% of the total thickness of the shingle.

It will also be understood that variations can be made in the molddesign, by varying angles, radiuses and the like to avoid excessivethinning of the capstock material, all with a view toward controllingthe capstock coverage of the core material, not only on the majorsurfaces, but also at the edges. Mold design can also be used to providerecesses or indentations in the lower surface of the shingle, thusallowing lesser amounts of material to be used.

By combining a skin material with a core material, such allows aneconomic advantage in that a greater amount of filler may be used tocomprise the core, which will be of less expense than the material thatcomprises the skin, without providing undesirable surface properties forthe skin, and without limiting the aesthetics of the product, becausethe core is, at least partially, encapsulated in an aestheticallypleasing and weatherable skin. Additionally, the core can be comprisedof a foam or microcellular foam material where reduced weight for theproduct is desired.

In some embodiments the shingle or tile is comprised of a core that ismade of a low molecular weight material such as polypropylene filledwith 40-80% by weight of recycled ash with suitable functionaladditives, encapsulated in a skin comprised of a film.

Such fillers for the core material can vary considerably and can bechosen from a group that includes, as examples, treated and untreatedashes from incinerators of power stations, mineral fillers and theirwaste, pulp and paper waste materials, oil shale, reclaimed acrylicautomotive paint and its waste and/or mixtures of any of these, or thelike.

The skin can be chemically cross-linked to increase its mechanicalproperties and weather resistance and/or flame resistance and cancontain functional additives such as pigments, UV light stabilizers andabsorbers, photosensitizers, photoinitiators etc. The cross-linking mayoccur during or after processing of the material. Such cross-linking canbe effected by means which include, but are not limited to, thermaltreatment or exposure to actinic radiation, e.g. ultraviolet radiation,electron beam radiation, gamma radiation, etc.

By way of example, the skin material is selected from a group ofthermoplastic materials comprising Polyolefins such as thermoplasticolefins, Polyethylene (PE), Polypropylene (PP), Polymethylpentene (PMP),Ethylene Acrylic Acid (EAA), Ethylene Methacrylic Acid (EMAA),Acrylonitrile Styrene Acrylate (ASA), Acrylonitrile Ethylene Styrene(AES) and Polybutene (PB-1), their copolymers, blends, and filledformulations, other polymers having high weather resistance such asPolyacrylates and fluoropolymers and/or their copolymers blends andfilled formulations. The skin material is preferably stabilized forUV-light and weathering resistance by using additives and additivepackages known in the state-of-the-art to be efficient. In addition, theskin materials may also contain various additives such as thermal andUV-light stabilizers, pigments, compatibilizers, processing aids, flameretardant additives, and other functional chemicals capable of improvingprocessing of the materials and performance of the product. Foamingagents such as azodicarbonamide may be used to reduce the density of theskin material.

By way of example, the core material may be selected from the groupcomprising of virgin thermoplastic polymer materials and elastomers andrubber including but not limited to Polyvinylchloride (PVC),Polyethylene (PE), Polypropylene (PP), Polybutene (PB-1),Polymethylpentene (PMP), Polyacrylates (PAC), Polyethyleneterephthalate(PET), Polybutyleneterephthalate (PBT), Polyethylenenaphthalate (PEN),Ethylene-Propylene-Diene Monomer Copolymers (EPDM), Styrene ButadieneStyrene (SBS), Styrene Isoprene Styrene (SIS), Acrylonitrile ButadieneStyrene (ABS), or Nitrile Rubber, their copolymers, binary and ternaryblends of the above, and filled formulations based on the above andother thermoplastic materials and elastomers with mineral, organicfillers, nanofillers, reinforcing fillers and fibers as well as recycledmaterials of the above polymers.

From the cost point of view, recycled and highly filled thermoplasticmaterials and recycled rubber (for example from tires) are preferable.The content of mineral fillers can be in the weight range from 5% to80%.

In addition, the core materials may also contain various additives suchas thermal and ultraviolet (UV) light stabilizers, pigments,compatibilizers, processing aids, flame retardant additives, and otherfunctional chemicals capable of improving processing of the materialsand performance of the product. Some flame retardants known to havenegative effects on weather resistance of polymers can still beeffectively used in the core material, the skin or capstock layerserving to protect the shingle from the effects of the weather. Chemicalfoaming agents such as azodicarbonamide may be used to reduce thedensity of the core material. Physical blowing agents, glass bubbles orexpanded polymer microspheres may also be used to adjust the density ofthe core material.

In making the products of this invention, the single layer 152 of skinor combined upper and lower layers 152 and 153, of the skin may comprisefrom 1% to 40% of the total thickness of the product, with the coreinside the skin being thicker between upper and lower surfaces andcomprising the remaining percentage of the total thickness of theproduct.

Examples of making shingles in accordance with this invention are asfollows.

Example 1

Pellets of a flexibilized polypropylene copolymer, 18S2A, available fromHuntsman Chemical, Salt Lake City, Utah, were combined in a WernerPfleiderer twin screw extruder with calcium carbonate, Hubercarb Q3,available from J. M. Huber Corporation, Atlanta, Ga., and a stabilizerpackage, FS-811, available from Ciba Specialty Chemicals, Tarrytown,N.Y., using gravimetric feeders to obtain a mixture that was 49.25 wt %polypropylene, 50 wt % calcium carbonate and 0.75% stabilizer package.This mixture was extruded as a strand and chopped into pellets of filledpolypropylene for later processing.

Example 2

Pellets of Example 1 were dried and fed into a single screw extruder,MPM 3.5 inch in diameter, 24:1 L/D, equipped with a flex lip die andextruded to form a sheet. The die was adjusted to produce an extrudatethat was about 19 inches in width and having a profile with varyingthickness across the sheet ranging from about 0.375 inches to 0.245inches. The sheet was extruded onto a first conveyor belt havingvariable speed matched to the extrudate speed. The temperature of thesheet was about 380 F when exiting the die.

When a section of sheet 13 inches in length had been extruded, the sheetwas cut from the die lip. While still hot, the section of 19″×13″ sheetwas carried to a second conveyor belt and transferred to and centered onthe lower plate of a mold having a size of 18″×12″. Infrared lamps wereprovided above the conveyor to maintain the temperature of the sheetduring transfer. On reaching the lower mold plate, the surfacetemperature was about 300 F. The upper portion of the mold, having asurface texture designed to represent the surface texture of a naturalslate, was brought into contact with the sheet on the lower plate andthe mold was closed in a platen press with 20 tons pressure to shape andform the sheet, with a slight excess of material being squeezed out ofthe mold.

Cooling was applied to the mold by means of water circulating coolinglines in the mold plates to cool the formed sheet to a solid state.After about 1 minute, the mold was opened to release a short cyclecompression molded synthetic roofing tile. The synthetic roofing tilehad cooled to a surface temperature of about 80 F on the side that hadbeen in contact with the bottom plate and to temperature of about 120 Fon the surface that had been molded by the top plate of the mold set.Excess material and flashing were cut off of the tile.

Example 3

Pellets of a flexibilized polypropylene copolymer, 18S2A, available fromHuntsman Chemical, Salt Lake City, Utah, were combined in a WernerPfleiderer twin screw extruder with calcium carbonate, Hubercarb Q3,available from J. M. Huber Corporation, Atlanta, Ga., using gravimetricfeeders to obtain a mixture that was 50 wt % polypropylene and 50 wt %calcium carbonate. This mixture was extruded as a strand and choppedinto pellets of filled polypropylene for later processing.

Example 4

Pellets of a flexibilized polypropylene copolymer, 1 8S2A, availablefrom Huntsman Chemical, Salt Lake City, Utah, were combined in a WernerPfleiderer twin screw extruder with calcium carbonate, Hubercarb Q3,available from J. M. Huber Corporation, Atlanta, Ga., and a stabilizerpackage, FS-811, available from Ciba Specialty Chemicals, Tarrytown,N.Y., using gravimetric feeders to obtain a mixture that was 79.25 wt %polypropylene, 20 wt % calcium carbonate and 0.75% stabilizer package.This mixture was extruded as a strand and chopped into pellets of filledpolypropylene for later processing.

Example 5

Pellets of filled polypropylene from Example 3 were dried and fed into afirst single screw extruder, MPM 3.5 inch in diameter, 24:1 L/D, toprovide core material. Separately, dried pellets of filled polypropylenefrom Example 4 and pellets of gray toner 60Z2274 available from PennColor, Doylestown, Pa., were fed using gravimetric feeders to obtain aratio of 2 wt % gray toner to 98 wt % filled polypropylene into a secondextruder, Prodex 2.5 inch in diameter 24:1 L/D, to provide capstockmaterial. The output of both extruders was fed through an adapter blockand a dual layer coextrusion block to a flex lip die and coextruded toproduce a sheet having a core of material from the first extruder bondedwith a coextruded capstock provided by the second extruder, with thelayer of capstock covering the top surface of the layer of corematerial.

The die was adjusted to produce an extrudate that was about 19 inches inwidth and having a profile with varying thickness across the sheetranging from about 0.375 inches to 0.245 inches. The relative rates ofextrusion from the two extruders for the capstock and the core layerswere controlled such that the capstock thickness was about 10% of thetotal thickness of the composite sheet, The sheet was extruded onto afirst conveyor belt having variable speed matched to the extrudatespeed. The temperature of the sheet was about 380 F when exiting thedie,

When a section of sheet 13 inches in length had been extruded, the sheetwas cut from the die lip. While still hot, the section of 19″×13″ sheetwas carried to a second conveyor belt and transferred to and centered onthe lower plate of a mold having a size of 18″×12″. Infrared lamps wereprovided above the conveyor to maintain the temperature of the sheetduring transfer. On reaching the lower mold plate, the surfacetemperature was about 300 F. The upper portion of the mold, having asurface texture designed to represent the surface texture of a naturalslate, was brought into contact with the sheet on the lower plate andthe mold was closed in a platen press with 20 tons pressure to shape andform the sheet, with a slight excess of material being squeezed out ofthe mold. The flow of material at the edges of the mold was such thatthe capstock thickness at the molded edges of the shape was maintainedto be least 4 mils over the entire top surface of the piece, even at theedges.

Cooling was applied to the mold by means of water circulating coolinglines in the mold plates to cool the formed sheet to a solid state.After about 1 minute, the mold was opened to release a short cyclecompression molded synthetic roofing tile having a core layer and acapstock layer. The synthetic roofing tile had cooled to a surfacetemperature of about 80 F on the side that had been in contact with thebottom plate and to temperature of about 120 F on the surface that hadbeen molded by the top plate of the mold set. Excess material andflashing were cut off of the tile.

Example 6

Dried pellets of filled polypropylene from Example 3 were fed into afirst single screw extruder, MPM 3.5 inch in diameter, 24:1 L/D, toprovide core material. Separately, dried pellets of filled polypropylenefrom Example 4, pellets of gray toner 60Z2274 and black accent colorpellets 68B282, available from Penn Color, Doylestown, Pa., were fedusing gravimetric feeders to obtain a ratio of 2 wt % gray toner, 1 wt %accent color pellet, and 97 wt % filled polypropylene into a secondextruder, Prodex 2.5 inch in diameter 24:1 L/D, to provide capstockmaterial. The output of both extruders was fed through an adapter blockand a dual layer coextrusion block to a flex lip die and coextruded toproduce a sheet having a core of material from the first extruder bondedwith a coextruded capstock provided by the second extruder, with thelayer of capstock covering the top surface of the layer of corematerial.

The temperatures in degrees Fahrenheit of the zones of the capstockextruder, the adapter, the coextrusion block and the die are notedbelow:

Barrel zone Adapter zone Co-Ex Die zone 1 2 3 4 1 2 3 block 1 2 3 320330 330 330 370 375 375 375 375 375 375

The die was adjusted to produce an extrudate that was about 19 inches inwidth and having a profile with varying thickness across the sheetranging from about 0.375 inches to 0.245 inches. The relative rates ofextrusion from the two extruders for the capstock and the core layerswere controlled such that the capstock thickness was about 10% of thetotal thickness of the composite sheet. The sheet was extruded onto afirst conveyor belt having variable speed matched to the extrudatespeed. The temperature of the sheet was about 380 F when exiting thedie.

When a section of sheet 13 inches in length had been extruded, the sheetwas cut from the die lip. While still hot, the section of 19″×13″ sheetwas carried to a second conveyor belt and transferred to and centered onthe lower plate of a mold having a size of 18″×12″. Infrared lamps wereprovided above the conveyor to maintain the temperature of the sheetduring transfer. On reaching the lower mold plate, the surfacetemperature was about 300 F. The upper portion of the mold, having asurface texture designed to represent the surface texture of a naturalslate, was brought into contact with the sheet on the lower plate andthe mold was closed in a platen press with 20 tons pressure to shape andform the sheet, with a slight excess of material being squeezed out ofthe mold. The flow of material at the edges of the mold was such thatthe capstock thickness at the molded edges of the shape was maintainedto be least 4 mils over the entire top surface of the piece, even at theedges.

Cooling was applied to the mold by means of water circulating coolinglines in the mold plates to cool the formed sheet to a solid state.After about 1 minute, the mold was opened to release a short cyclecompression molded synthetic roofing tile having a core layer and avariegated capstock layer, the capstock having a base gray color withgray-black accent streaks simulating the color appearance of naturalslate. The synthetic roofing tile had cooled to a surface temperature ofabout 80 F on the side that had been in contact with the bottom plateand to temperature of about 120 F on the surface that had been molded bythe top plate of the mold set. Excess material and flashing were cut offof the tile.

Example 7

Example 7 was prepared similarly to Example 6, except that the graytoner 60Z2274 was omitted from the capstock and the capstock compositionwas metered to include 1 wt % of the accent color pellet and 99 wt % ofthe filled polypropylene of Example 3. The short cycle compressionmolded synthetic roofing tile having a core layer and a variegatedcapstock layer was produced, the capstock having a light color withgray-black accent streaks simulating the color appearance of naturalslate.

Example 8

Example 8 was prepared similarly to Example 6, except that thetemperature profile of the capstock extruder was at a slightly highertemperature as shown in the table below.

Barrel zone Adapter zone Co-Ex Die zone 1 2 3 4 1 2 3 block 1 2 3 350350 350 350 370 375 375 375 375 375 375

The synthetic roofing tile having a core layer and a capstock layer wasproduced, the capstock having an even gray color, the accent colorpellets having melted out into the mixture in the extruder.

Example 9

Example 9 was prepared similarly to Example 6, except that a differentaccent color pellet, 60B281, available from Penn Color, was used with acapstock composition metered to 2 wt % gray toner 60Z2274, 2 wt % accentcolor pellet 60B281 and 96 wt % filled polypropylene of Example 3. The60B281 had a higher softening temperature than the accent color pelletused in Example 6, so the temperature profile in the capstock extruderwas modified as noted in the table below.

Barrel zone Adapter zone Co-Ex Die zone 1 2 3 4 1 2 3 block 1 2 3 390390 400 380 370 375 375 375 375 375 375

In the synthetic roofing tile of Example 9, having a core layer and acapstock layer, the capstock had a base gray color, but also hadgray-black spots where the accent color pellets had not meltedsufficiently during the processing to produce the streaking effect.

It will be apparent from the foregoing that various other modificationsmay be made in the process steps of this invention, in the apparatus, orin the resultant roofing shingle or tile of this invention, all withinthe spirit and scope of the invention as defined in the appended claims.

1. A process of making shingle or tile products comprising the steps of:(a) co-extruding heated, unshaped thermoplastic materials from moltenstates in a co-extruder and discharging those unshaped thermoplasticmaterials from a mouth of the co-extruder into a formed, continuousshaped extrudate that includes a core material with a capstock productsurfacing material on and adhered directly to at least a portion of amajor surface of the core material of the continuous shaped extrudateand then directly cutting the extrudate into a plurality of preliminaryproduct shapes while the preliminary product shapes are above asolidification temperature; (b) then delivering the preliminary productshapes serially along a path while allowing the preliminary productshapes to cool an amount that maintains the temperature of thepreliminary product shapes above a solidification temperature; (c) thendelivering the cooled but still non-solid preliminary, product shapes toa compression mold; (d) molding the preliminary product shapes in themold by compression molding the preliminary product shapes tosubstantially their final product dimensions and controlling internalstress development of the product shapes in the mold by having thecapstock product surfacing material being at a greater temperature inthe mold than the temperature of the core material in the mold; and (e)then discharging the molded products from the mold and allowing themolded products to cool to a solid state; wherein the compressionmolding step includes causing the capstock product surfacing material toflow over at least one edge of the core material to cover that edge ineach molded product.
 2. The process of claim 1, wherein the preliminaryproduct shapes are of a first size and the compression mold has a secondsize, and said first size is selected from the group consisting of thesame as and greater than the second size.
 3. The process of claim 1,wherein the preliminary product shapes have dimensions, and saiddimensions are equal to or greater than the final product dimensions. 4.The process of claim 1, wherein the step of co-extruding includesco-extruding more than two layers of thermoplastic material.
 5. Theprocess of claim 1, wherein the delivering step includes transportingthe preliminary product shapes to a compression mold, by transportmeans.
 6. The process of claim 1, including the step of placing thepreliminary product shapes between spaced apart male and femalecomponents of a mold that together have formed interiors that definesubstantially the final shape of the products and bringing the saidcomponents together under sufficient compression force to shape thepreliminary product shapes into substantially the final dimensions ofthe products.
 7. The process of claim 6, including the step of cuttingperipheral material from edge portions of the products.
 8. The processof claim 7, wherein the step of cutting peripheral material is done aspart of and substantially simultaneously with the compression moldingstep.
 9. The process of claim 6, including the step of cooling the moldduring at least a portion of the compression molding step.
 10. Theprocess of claim 1, wherein a transverse cutter serially cuts offextrudate being extruded from the co-extruder into the preliminaryproduct shapes.
 11. The process of claim 6, including the step ofpushing the products away from the interior of the mold.
 12. The processof claim 11, wherein the pushing step is done with spring pins.
 13. Theprocess of claim 6, including the step of pushing the products away fromthe interior of the mold.
 14. The process of claim 1, wherein thecompression molding step includes forming product fastening areas ineach product, that are of reduced material thickness relative to thethickness of most of the remainder of the product.
 15. The process ofclaim 1 including the step of providing the core material with a flameretardant.
 16. The process of claim 1, wherein the capstock productsurfacing material in the mold is at a temperature of about 120° F. andthe core material in the mold is at a temperature in a range of 70° F.to 80° F.